Japanese Patent HEI 3-40464(1991) discloses a battery holder for a dish-shaped battery. That battery holder has a main body with a plate that faces one surface of the dish-shaped battery and has an area that corresponds to the circumferential area of the battery. The other surface of the battery is exposed. A notch is formed in a part of the circumferential area of the main body of this holder. A first terminal that has sufficient elasticity to force and press the battery circumference toward the direction of the notch is mounted on the side opposite to the notched area in the inside of the circumferential part.
A retainer provided near the first terminal and the notched part engages the otherwise exposed surface of the battery to prevent the battery from falling out of the holder. A second terminal in the main body of the holder forces and presses the battery contained in the main body of the holder against the retainer.
To install the battery in the battery holder, the battery is inserted from the notched side against the first terminal, elastically deforming the portion of the first terminal in contact with the battery toward the side of the inserting direction. In this state, the battery is forced into the main body of the holder against the elastic force of the second terminal. The circumference of the battery is thus forced against the inner surface in the circumferential part near the notched area of the main body of the holder by the elastic force exerted by the first terminal. At the same time the other surface of the battery is held by the retainer, to keep the battery in the battery holder.
When removing the battery, the notched part must be pushed from the side of the notched area firmly in the direction of the first terminal and the battery then must be removed by using a finger tip while maintaining this state. This separates a part of the battery from the retainer on the notched side, allowing the battery then to be removed by the users fingers. Thus, a laborious technique is required to remove the battery, and the battery cannot be removed from the battery holder by the single touch of a finger. Also, it is difficult to remove the battery, without applying an excessive force.
Furthermore, if one wants to install a new battery in the battery holder, the battery must be installed by pushing the battery from the notched side toward the first terminal and the battery must then be forced and pressed into the main body of the holder against the elastic force of the second terminal in this state. Thus, the operation is awkward, and the battery cannot be installed by a single touch of one's finger.
Many other examples are known of holders for batteries, including coin type batteries. Principal among these are the following: U.S. Pat. No. 4,070,821 discloses a spring that simultaneously retains two batteries in a watch while the watch back is in place. To remove the batteries it is necessary to remove the watch back and the spring. U.S. Pat. No. 4,107,400 discloses a button-type battery that is retained inside an opening by a hatch cover to which the battery is adhered by a non-permanent adhesive connection. A grip holds the battery for removal along with the hatch cover. U.S. Pat. No. 4,223,076 discloses a battery casing that has a lid that closes a battery chamber. The lid is directly mounted on the body of the battery casing. U.S. Pat. No. 4,495,257 discloses a battery holder for a cylinder cell having resilient contacts at its ends. Terminals project through its bottom for printed circuit board mounting, or flat terminals with eyelets project from the top of the holder. The holder comprises three parts: a casing, a positive terminal and a negative terminal. U.S. Pat. No. 4,653,822 discloses a battery that is stored in a chamber in which one contacting electrode provides sufficient contact force to retain the battery even in the absence of a bottom plate. The battery is inserted downwardly against the electrode and covered by a battery lid. U.S. Pat. No. 4,658,151 discloses a cup-shaped plastic housing for a long lived battery. The battery is placed in the housing and fixed in place by a casting resin resistant to the battery electrolyte. U.S. Pat. No. 4,992,987 discloses a battery package that has a battery contacted with a bar across its diameter that holds the battery in place. A sealing composition envelops the battery contacts. U.S. Pat. No. 5,075,182 discloses a flat battery installed in a holder by use of a battery handle that is attached to the battery and keyed to assure proper installation of the battery. U.S. Pat. No. 5,077,572 discloses a housing for a backup battery is formed within a chamber of a camera body adapted to receive the main power battery. The backup battery is held within the housing by pressure from an electric pole and a support wall. To eject the battery an ejecting lever is rotated, pushing the battery from the housing into the main battery chamber. U.S. Pat. No. 5,149,604 discloses a battery holder for two batteries that prevents them from being simultaneously removed, which would risk the loss of all memory contents. The batteries are retained in holes, covered with pressing plates that are held in place by screws. The configuration prevents the simultaneous removal of the screws necessary to remove both batteries in a single operation. U.S. Pat. Nos. 5,187,026 and 5,316,873 disclose a battery adapter for a disc shaped battery that has an outer shape and terminal location to allow the disc battery to fit devices calling for cylindrical batteries. To replace the disc battery it is necessary to open a door in the adapter, to pivot a connector away from the surface of the disc battery and to remove the battery from its resting location. U.S. Pat. No. 5,187,746 discloses a hearing aid battery provided in a water tight container that permits the entrance of air to the battery. The insertion of a battery requires placement of the battery in a cylindrical chamber after lifting a flap. A slide member further locks the combination. U.S. Pat. No. 5,188,912 discloses a battery holder that is inserted in a direction parallel to the electrode surfaces of the battery. The battery is slid into the holder which is in turn slid into a receiver for the holder that contains the terminals that contact the battery holders. To remove the battery, the holder is removed from the receiver and the battery extracted from the holder. U.S. Pat. No. 5,328,781 discloses a battery holder for two disc batteries which prevents the simultaneous removal of both. The batteries are inserted by being pressed downwards against an upward spring force. Cut sections of the holder are provided to assist in removal of the batteries, with a switch section that can cover a cut to prevent removal of the corresponding battery. A lock holds the switch in place.
It is an object of this invention to remove the above-described difficulties of the prior art and to provide a battery holder for coin cells (dish shaped batteries) that allows the battery to be installed and removed easily and precisely.